In our September update we look at smoke detectors, electrical terminology, electrical efficiency, the ‘in’s and out’s’ of different lighting technologies and their relative advantages and disadvantages and finally our approach to the installation of induction cooktops and their benefits.

Replace Old Smoke Detectors – Always Use Photoelectric Type Smoke Detectors

Walking past Leichhardt fire station we observed a sign on the station window (image below) recommending smoke alarms be Electrician Inner West - September 2016 Electrician Updatereplaced every 10 years with the latest photoelectric type smoke detectors. This advice has been in place for several years in N.S.W. and ionisation type smoke detectors are no longer recommended.
Photoelectric alarms operate using light sources and light detectors. When the light source, typically an l.e.d. shines on a photo detector an electrical signal is generated. When smoke partially blocks the transmission of light onto the photo detector the electronics in the smoke alarm unit detects these changes in electrical output from the photoelectric sensor and creates a signal that drives an electrical or solid state relay that then powers an audible alarm, warning that there is smoke present. This method of detecting the presence of smoke is considered to be far less prone to ‘false alarms’ and reacts very quickly to smoke in comparison the the older ‘ionisation’ type smoke detectors that use low level radioactive elements to detect the presence of smoke.

You should contact a suitably licensed electrician to check out which type of smoke alarms that you currently have installed in your home and the location of the detectors. It is recommended that smoke detectors are ideally 240 volt (mains powered) and have a battery backup that ensures the smoke detectors still function correctly in the case of a power outage. Rather than installing ‘stand alone’ detectors, it is recommended that the detectors are ‘hard wired’. Again, this needs to be done by an electrician.
The bottom line is that is is a legal requirement to have smoke detectors installed, but even more important is to understand that smoke alarms really do save lives, so getting an electrician experienced in installing and testing them should be your first step in protecting your family and home from the risk of smoke and fires.

Wattage, Voltage and Electrical Current – Electrician Tips and Advice.

We have all seen different electrical appliances, light bulbs, air conditioning units and devices with different electrical tipselectrical ratings on them. So what is the significance of wattage? Wattage is a measure of the electrical power that a device consumes. This is important because it ultimately determines factors like the cost of running an electrical device, the environmental friendliness or not of the device and the ‘power’, or electrical “strength” that the device runs at. A higher wattage light bulb will burn brighter than a low wattage bulb of the same type. Wattage in electrical engineering terms is a measure of the voltage times the electrical current that the device draws (Watts = V x I, where v= voltage and I=current). In general we want the lowest possible electrical wattage that will produce the desired outcome – be it in the amount of light emitted, the heat from an electrical heater or the amount of air moved by a ceiling fan, for example.

Electrical Efficiency

Electrical efficiency and energy efficiency, in general, are a measure of the percentage of electrical input to a device (a light bulb for example) compared to the output from the device. In the case of l.e.d. lighting, for example, they are extremely ‘energy efficient’ because most of the electricity that powers the bulb is transformed into light output without ‘wastage’ of the electrical input energy into heat, which is essentially wasted energy. L.e.d. lighting systems that we install, typically run at around 80 to 90 percent efficiency. Compare this to incandescent light bulbs that can run at less than 50 percent efficiency. Using energy efficient devices in the home and looking for high star energy rated appliances makes sense financially and environmentally. There is useful consumer information on energy efficiency at

Lighting – Lifespan Of Different Light Bulb Technology

Just as the electrical efficiency of light bulbs is important – to ensure we choose lighting that converts as much electrical power into visible light with minimal losses, it is also important to consider light bulb longevity. Using energy efficient light bulbs will save on power bills, but if we have to replace them very frequently this will erode any savings made by using low energy input lighting. So how do the different light technologies currently stack up in terms of their lifespan? Here we look at the number of hours of operation, or life expectancy, that we can expect from the most commonly used light bulbs:

1. L.e.d. Lights. The commonly quoted figure for l.e.d. light bulb life expectancy is around 40,000 hours. This figure can be extended to over 50,000 hours for some of the ‘high end’ l.e.d. light bulbs. L.e.d. light bulbs are manufactured by integrating several light emitting diodes into one unit. The quality of these individual l.e.d.’s goes a long way to determining how long the completed light bulb will last.

2. C.F.L. or compact fluorescent light bulbs were the flavour of the month for energy efficient lighting a few years ago

c.f.l. light bulb image

Typical C.F.L. Bulb

before l.e.d. technology came to the forefront. The lifespan of compact fluorescent lights are typically around 7,000 to 16,000 hours, again depending on the manufactured quality of the light bulbs and the pattern of usage of the bulbs. They still offer relatively good energy efficiency and life spans.

typical halogen lamp image

Typical halogen lamp image

3. Halogen Lamps. Surprisingly, we still see a large number of halogen globes in use. They tend to run hot and are relatively inefficient energy wise. Their life span drops down a notch from c.f.l. and l.e.d. technology lamps and are typically quoted at 1,500 to 4,000 hours.

4. Incandescent Light Bulbs. The humble ‘edison’ style incandescent light bulb has a low lifespan ranging from 750 hours to 1,500 hours. Increasingly they make little sense on energy efficiency, lifespan or economics.

Inside The L.E.D. Bulb – Electrical Insights

From the above information we can see there are huge benefits in installing l.e.d. light bulbs and l.e.d. light fittings wherever possible when you renovate, upgrade lighting systems or simply change a light bulb (or call a licensed electrician to change them). So lets look at some of the ‘hard facts’ around l.e.d. lighting.

1. L.E.D. Bulb Colour Spectrum. How is the ‘feel’ and appearance of l.e.d. light specified? The appearance of light from any light source is derived from the spectral colour of the light. It may appear to be a ‘cool’ whitish coloured light, a ‘warm’ yellower tinged light or

LED lighting in's and out's

L.E.D. Light Bulb

even a mid spectrum ‘daylight’ coloured light. These colours of the emitted light make a huge difference to the feel of lighting in any room or outdoor area. The colour of light is specified ( in lighting) by a temperature, generally in Kelvin, A “warm” l.e.d. light bulb will generally be specified within the 2000 – 3000 kelvin (notated as ‘K”) range. The cool, whitish l.e.d. light bulbs will be specified within the range of 3100 – 4500 Kelvin and daylight appearance l.e.d. light bulbs will have a range of 4600 – 6600 Kelvin. When you purchase l.e.d. light bulbs you will see the Kelvin rating of the bulb specified and generally the ‘spectral colour’ of the light (warm, cool or daylight).

2. Running Costs Of L.E.D. Bulbs. We can take an example of a 10 watt l.e.d. bulb to look at how much it actually costs to power l.e.d. lighting. A 10 watt l.e.d. light bulb emits approximately the same amount of ‘usable’ light that a ‘standard’ 60 watt incandescent light bulb. Assuming we run the light bulb is run 10 hours per day and an electricity cost (in N.S.W.) of 20 cents per kilo watt hour, this l.e.d. light bulb would cost just 2 cents per day to run or $7.30 per year.

3. Lifespan Of L.E.D. Bulbs. Using the above example of 10 hours per day running time for our l.e.d. light bulb and an ‘average’ life expectancy of 40,000 hours, we would expect out ‘sample’ light bulb to last an amazing 10.95 years!

Electrical Installation Of Induction Cooktops

Induction cooktops are now very popular in domestic kitchens as they are faster, safer and more energy efficient than gas and traditional electric cooktops. To many people the most important features of induction cooktops is that you can adjust the cooking heat instantly and with great precision.

How Induction Cooktops Work

An induction burner consists of a ceramic plate with an electromagnetic coil beneath it. When you turn on the induction cooktopburner, an electric current runs through the coil, generating a fluctuating magnetic field, but no heat on the burner itself. Once you set an iron or stainless steel pan on the burner the magnetic field induces many smaller electric currents intp the pan’s metal. Iron is a poor conductor of electricity, so as all these small currents run through the iron much of the energy is converted to heat. 

Benefits Of Induction Cooktops

Induction is the first technology that offers all of the benefits of cooking with gas, with none of the drawbacks. Until now, gas has always outperformed electric cooking surfaces. Some advantages of Induction cook tops are:

  1. Faster – Because energy is directly transferred within the pan metal, cooking on an electric induction range is extremely fast – even faster than gas.

        2. Safer – Electric induction cooktops are much safer than gas or other electric surfaces, since there is no open flame, red-hot coil or other radiant heat source to ignite fumes or flammable materials.

        3. Cleaner – With no grates or grease catch to worry about, clean up is a breeze. Just use a damp cloth and wipe over the flat, easy-to-clean surface.

       4. Cooler – Traditional gas or electric ranges waste up to half the heat they generate. The waste heats the kitchen instead of the food. With an electric induction range, almost no ambient heat is produced, since all the heat is being generated in the pan itself.

       5. Cheaper. Induction cooking is far more energy efficient than gas or traditional electric ranges. When you remove the pan from the induction cooking surface, the induction cooktop immediately goes into standby mode, which uses almost no energy whatsoever.

Induction cooktops are great for high-heat cooking, they offer the chef excellent temperature precision when it comes to simmering and melting. If an induction cooktop is to be installed into an existing kitchen different measurements need to be taken into consideration to ensure that it will be suitable for the existing circuit, as induction cooktops will generally be a large load on the existing electrical circuits.

Induction cooktops in kitchens need to be installed so that they conform to various requirements and so that they honour the manufacturer’s warranty and meet Australian standards. Induction cooktops use innovative technology to deliver fast and impressive results on the stove.